1. Field of the Invention
The present invention relates to substantially or completely inorganic liquid filler compositions and to the consolidation/sealing of ground formations and building materials therewith, in particular via injection technique.
2. Description of the Prior art
The consolidation/sealing of ground formations and building (construction) materials typically entails injecting liquid fillers of various types into the fissures, cavities or interstices thereof, to modify the characteristics of the treated site.
These modifications either improve the mechanical properties of the site in the case of consolidation, or reduce permeability in the case of sealing. The conjoint modification of both properties via injection technique is also possible.
Until recently, ground formation or construction material sealing and consolidation was principally carried out by injecting organic liquid fillers therein. However, products of syneresis of these liquid fillers (decomposition of the chemicals which are injected or formed) can pollute the groundwater table and surface waters.
Preservation of the groundwater table and surface waters such as watercourses and reservoirs is thus a current major concern among those skilled in the art of sealing and/or consolidation of a variety of substrates, particularly via injection technique.
Consequently, a number of inorganic liquid fillers have been tested for such purposes.
Research conducted vis-a-vis the need to satisfy new technological and economic constraints imposed by ecological considerations is widely described in the literature, both patent and otherwise.
For example, FR-A-2,571,734 describes an aqueous injectable liquid filler for ground consolidation and/or sealing which comprises fine particles of amorphous silica and particles of slaked lime.
This liquid filler, however, has a setting time which is too long (about 2 days).
FR-A-2,528,441 describes a ground sealing and/or consolidating agent comprising a specific concentrated soda solution of silica and, optionally, lime or a calcium salt. The dissolved silica reacts with the calcium to form crystals of hydrated calcium silicates.
The problem with the aforesaid liquid fillers, however, is that they either exhibit unsatisfactory final mechanical properties, or a setting time which is too short and incompatible with the desired application, or, again, that the initial viscosity thereof is too high.